The first impressions of the surface printed KGV series is that it superseded the kangaroo issues and that all denominations and most colours were issued more or less at the same time in some sort of set.
KGV never superseded the Roo. Both were issued contemporaneously as a single unified definitive known as the 1st General Series of the Australian Commonwealth. (The KGVI zoologicals were the 2nd General Series, and so on). The name General Series was the post offices attempt at defining definitives:- stamps intended to be on sale for a very long time.
The bewildering array of colours, printers and perforations can be understood better if one realises that for some years the only KGV’s on issue comprised FOUR denominations only of ½d, 1d, 4d and 5d. (the 1½d was introduced shortly afterwards due to postal increases, but, the essence was that only four denominations were originally produced as a ‘set’)
Secondly, it would appear that the KGVs in general come from a single die and are more or less all the same, barring the changes of denomination.
In fact, there was one critical difference between the 1d KGV and all others (initially). The 1d was created in London by Perkins Bacon using four STEEL plates. All other denominations were produced, each from their own separate die, in Australia, using electroplates.